Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (05): 1169-1176.doi: 10.3866/PKU.WHXB201203012

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Preparation and Electrochemical Performance of LiTi2(PO4)3/C Composite Cathode for Lithium Ion Batteries

YUAN Zheng, CUI Yong-Li, SHEN Ming-Fang, QIANG Ying-Huai, ZHUANG Quan-Chao   

  1. Li-Ion Batteries Laboratory, School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116, Jiangsu Province, P. R. China
  • Received:2011-11-18 Revised:2012-02-20 Published:2012-04-26
  • Contact: ZHUANG Quan-Chao
  • Supported by:

    The project was supported by the Fundamental Research Funds for the Central Universities, China (2010LKHX03, 2010QNB04, 2010QNB05) and Innovation and Ability Enhancement Funds for Fostering Subject of China University of Mining and Technology (2011XK07).

Abstract: LiTi2(PO4)3/C composite with a Na+ superionic conductor (NASICON)-type structure was prepared by a sol-gel method. The LiTi2(PO4)3/C composite had a good NASICON structure and good electrochemical properties as revealed by X-ray diffraction (XRD), scanning electron microscopy (SEM), charging/discharging tests, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The first discharge capacity was 144 mAh·g-1. The EIS results indicated that there appeared semicircles respectively representing the solid electrolyte interface (SEI) film as well as the contact resistance, charge transfer resistance, and phase transformation resistance in the initial lithiation process of LiTi2(PO4)3/C composite electrode. The chemical diffusion coefficients of intercalation and de-intercalation of Li+ in the LiTi2(PO4)3 cathode material were calculated to be 2.40×10-5 and 1.07×10-5 cm2·s-1, respectively.

Key words: LiTi2(PO4)3/C composite material, Electrochemical impedance spectroscopy, Solid electrolyte interface film, Contact resistance, Phase transformation, Diffusion coefficient